Part 1 of A Historic Review of the Canadian Nuclear Industry: The Early Years

The below is part one of a five-part series detailing the history of Canada’s nuclear industry written by Michael Alexander Sinclair. It was originally submitted as an essay on November 15, 2017 for Ryerson University’s HST 701: Scientific Technology & Modern Society, and has since been modified for publication onto the Mackenzie Institute website.

When uranium was first discovered in 1789 by a German chemist named Martin Klaproth, he named it after the planet Uranus, so named for the primal Greek god that originally ruled the universe.1 Historically, advancements in nuclear research have occurred at very rapid rates. Starting in earnest in 1895 with the original discovery of ionizing radiation, German scientists Otto Hahn and Fritz Strassmann had already demonstrated by 1939 that nuclear fission did not only produce energy but also additional neutrons that could cause other nearby uranium atoms to fission.2  The potential applications for this exciting new discovery were boundless, and Canada was quick to respond to the emerging field of nuclear applications. Canadian scientists were involved in nuclear research at the beginning, and in the 1930s the country was at the forefront of nuclear science, technology and expertise. Today, there is no question that Canada is still not only a major participant but also a leader within the international nuclear community. Deeply engrained in both the country’s history and its modern society, it is difficult to imagine Canada as a country without its nuclear industry, and by extension its nuclear reactors.

Figure 1 “Ernest Rutherford”, Atomic Heritage Founda-tion, Available online at Ac-cessed May 07, 2018.
Figure 1 “Ernest Rutherford”, Atomic Heritage Founda-tion, Available online at Ac-cessed May 07, 2018.

The scientific research that Canada has performed in its quest to develop nuclear applications has furthered scientific knowledge and advanced the global understanding of the benefits of nuclear power. As a global leader in nuclear research, Canada’s achievements have ensured its place among the nuclear nations. The technology and innovation born from Canadian research are the fundamental reasons behind its success. The Canadian nuclear industry has produced elemental isotopes for medical purposes that Canada has used domestically as well as supplied to the rest of the world.  The technologies and scientific fields built around these isotopes have had an enormous impact globally . As a direct result of Canada’s research and development in medical applications of nuclear radioisotopes, today over 40 million nuclear medicine procedures are conducted annually in over 10 thousand hospitals globally. One specific isotope produced by Canadian reactors, Cobalt-60, is used in over 10 million cancer treatment procedures annually, and since the inception of this medical advancement Canada has been the major global supplier of this life-saving isotope.3

Canada has also produced the CANDU reactor, standing for CANada Deuterium Uranium, which cemented the country’s place as a global player in nuclear power production expertise. It is designed to use natural uranium as fuel, possible through the use of deuterium, called heavy water, as a neutron moderator. This type of reactor has many advantages over conventional light water reactor designs that use enriched uranium fuels cooled and moderated by pressurized light water. These include the ability to be refueled online, lower cost fuel, the potential to use alternate fuels, and design aspects that make these reactors exceptionally safe. CANDU reactors feature simple designs and manufacturing. These characteristics provide developing nations the ability to utilize inexpensive nuclear power rather than restricting technology to only the first-world nations that have access to more complicated and heavier industrial manufacturing processes. Currently, there are 31 CANDU reactors in the world, spread globally amongst seven countries, with 19 reactors deployed across Canada and 12 reactors exported to South Korea, Romania, Pakistan, India, China and Argentina Additionally, there are 13 reactor designs based on the CANDU design.

Figure 2”Frederick Soddy”,, Available online at Accessed May 07, 2018.
Figure 2”Frederick Soddy”,, Available online at Accessed May 07, 2018.

In order to provide context, this paper will examine events that occurred at the very beginning of the nuclear industry within Canada, where one of the most important and fundamental contributions to nuclear physics occurred. Around the start of the 20th century Ernest Rutherford,  a New Zealand born physicist who was called “a second Newton” by none other than Albert Einstein, was hired by McGill University. After becoming the first research student t o study at the University of Cambridge’s Cavendish Laboratory in London, England, Rutherford made the move to Canada where his scientific discoveries would completely change our understanding of matter5 Rutherford, often called “the father of nuclear physics” established what came to be known as the Montreal Laboratory at McGill in Quebec, Canada. With the assistance of Frederick Soddy, Rutherford was awarded the Nobel Prize for Chemistry in 1908 for his work conducted in Canada.  The paper he and Soddy authored ushered in a new age of nuclear physics and established the base upon which the future of nuclear development was to be built. As nuclear theory developed further on a global scale over the course of the next four decades, a new goal to harness the phenomena of atomic disintegration and the energies it can produce appeared: how to physically create a nuclear chain reaction using fissile uranium atoms.

In 1940, the first attempt to achieve a self-sustained critical nuclear reaction in Canada was by George C. Laurence  under the Canadian National Research Council (NRC). Laurence was a Canadian nuclear physicist who received his doctorate degree under Rutherford, at the Cavendish Laboratory from Cambridge University. Laurence returned to Canada to join the NRC in 1930 where he established a laboratory that focused on the study of radiation in cancer treatment11 12 13

Laurence’s goal in 1940 was to create a self-sustaining nuclear reaction. It was already known at this point that nuclear fission could be achieved when a uranium atom was struck by a neutron. It was also known  at this time by scientists around the world that moderating neutrons improved the chance of fission. However, key challenges during the early days of nuclear science was in producing large scale quantities of sustainable energy under controlled conditions.

Figure 3 “George C. Laurence”, Atomic Herit-age Foundation, Available online at Accessed 07 May 2018.
Figure 3 “George C. Laurence”, Atomic Herit-age Foundation, Available online at Accessed 07 May 2018.

Bulk fission would only be possible if the uranium fuel could capture at least as many neutrons as the reaction itself was producing. There had been previous experiments involving uranyl nitrate dissolved in normal water that had failed. It appeared more promising when using heavy water, formally called deuterium, which are water molecules composed of hydrogen atoms that contain two neutrons instead of just one neutron. Heavy water, however, was both rare and expensive to produce. The British possessed the majority of the world’s supply at this time. Thus, Laurence chose to use carbon instead as a moderator for the first Canadian nuclear reactor and uranium oxide as the fuel. The experimental reactor was humble in design; Paper bags of uranium oxide were dispersed amongst paper bags of carbon, contained within a gigantic paraffin wax-lined wooden bucket. Although the rate of neutron capture and release by fission was measurable, it was found that the capture rate was a few percentages lower than the production rate; the reactor was unable to achieve criticality.14

Stay tuned for part two of five coming soon.


  1. “Outline History of Nuclear Energy”, World Nuclear Association,, Accessed 01 November 2017; F. H. Kim Krenz, Deep waters: the Ottawa River and Canada's nuclear adventure (Montreal: McGill-Queen's University Press, 2004), p62, 64; Atsma, Aaron J. "Ouranos." Theoi Project - Greek Mythology. Accessed 05 May 2018.
    Netherlands & New Zealand, Theoi Project © Copyright 2000 - 2017
  2. “Outline History of Nuclear Energy”, World Nuclear Association; F. H. Kim Krenz, Deep waters.
  3. "Nuclear Medicine", Canadian Nuclear Isotopes Council, Available online at Accessed 07 May 2018.
  4. “CANDU Technology”, Canadian Nuclear Association, Available online at Accessed 07 May 2018; “Nuclear Power in Canada”, World Nuclear Association, Available online at, Accessed 07 November 2017.
  5. Editors, “Ernest Rutherford”, A&E Television Networks (2017), The website, Available online at Accessed 03 August 2017.
  6. "It is probable that all heavy matter possesses - latent and bound up with the structure of the atom - a similar quantity of energy to that possessed by radium. If it could be tapped and controlled what an agent it would be in changing the world's destiny! The man who put his hand on the lever by which a parsimonious nature regulates so jealously the output of this store of energy would possess a weapon by which he could destroy the earth if he chose." - Frederick Soddy; Lecturing on radium to the Corp. of Royal Engineers; 1904.
  7. Editors, “Ernest Rutherford; “Sir Ernest Rutherford (1871–1937)”, McGill University,, Accessed 12 November 2017; “Ernest Rutherford – Biographical”, Nobel Media AB (2014). Available online at: Accessed 12 November 2017.
  8. E. Rutherford M.A. D.Sc. & F. Soddy M.A., “Radioactive Change” The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, v. 5(29) (1903).
  9. “Sir Ernest Rutherford (1871–1937)”, McGill University; Editors, “Ernest Rutherford”; “Ernest Rutherford – Biographical”, Nobel Media AB.
  10. “Sir Ernest Rutherford (1871–1937)”, McGill University; “Ernest Rutherford – Biographical”; Editors, “Ernest Rutherford”; "Rutherford, Ernest.", Complete Dictionary of Scientific Biography,, Available online at Accessed 06 May 2018.
  11. George C. Laurence, Early Years of Nuclear Energy Research in Canada (Publication Location Unknown: Atomic Energy of Canada Limited, 1980), p.2-4. Available online at: Accessed 07 November 2017; “George C. Laurence (1961–1970)”, Canadian Nuclear Safety Commission,, Accessed 12 November 2017.
  12. In 1966, Laurence received the Medal for Achievement in Physics from the Canadian Association of Physicists and the W.B. Lewis Medal from the Canadian Nuclear Association in 1975 in recognition of his contributions to early nuclear research in Canada. He was also awarded/inducted as a Member of the Most Excellent Order of the British Empire (MBE) award for his scientific contributions during The Second World War.
  13. The first successful self-sustained critical nuclear reaction was the Chicago Pile-1, which first went critical on December 2nd, 1942 through the work of Enrico Fermi and other scientists at the Metallurgical Laboratory in the University of Chicago, Illinois, United States of America. – “Chicago Pile-1”, Atomic Heritage Foundation, Available online at Accessed 07 May 2018.
  14. George C. Laurence, Early Years of Nuclear Energy Research in Canada; F. H. Kim Krenz, Deep waters: the Ottawa River and Canada's nuclear adventure, p. 79.
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Michael Sinclair
Michael A. Sinclair is a former Research & Development tech from Canadian Nuclear Labs where he gained his background in nuclear science and technology. He graduated from Brock University with an Honours Bachelor of Science Degree in Physics and is now currently studying computer engineering at Ryerson University to pursue his passion in electronics and instrumentation design. He is also an avid cyclist who enjoys travelling, reading and programming.